Actuator curve embedding – an advanced actuator line model

2017 ◽  
Vol 834 ◽  
Author(s):  
Pankaj K. Jha ◽  
Sven Schmitz
Keyword(s):  
Boundary Layer ◽  
Body Force ◽  
Turbine Blades ◽  
Predictive Capability ◽  
Wind Turbine Blades ◽  
Line Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Actuator Line Model ◽  
Nrel Phase Vi

This article describes an actuator curve embedding (ACE) concept to model arbitrary lifting lines using body forces within large-eddy simulation (LES). The new method removes some inconsistencies in body-force projection of the actuator line model (ALM) commonly used to represent wind turbine blades in atmospheric boundary-layer simulations. The concept and algorithm of ACE are presented followed by selected results for various blade planform and tip shapes that signify both the predictive capability and the advantages of the ACE concept. Examples include an elliptic wing, the NREL Phase VI rotor in parked and rotating conditions, and the NREL 5-MW turbine.

RESEARCH OF THE ROTATIONAL EFFECTS ON THE BOUNDARY LAYER OF WIND TURBINE BLADES

2009 ◽  
Vol 23 (03) ◽  
pp. 505-508 ◽  
Author(s):  
RUI YANG ◽  
REN-NIAN LI ◽  
WEI HAN ◽  
DE-SHUN LI
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Aerodynamic Coefficients ◽  
Wind Turbine Blades ◽  
Pressure Distributions ◽  
Rotating Blade ◽  
Show Evidence ◽  
Layer Flow ◽  
Nrel Phase Vi

The flow field past the rotating blade of a horizontal axial wind turbine has been modeled with a full 3–D steady–RANS approach. Flow computations have been performed using the commercial finite–volume solver Fluent. The NREL phase VI wind turbine blade sections from the 3–D rotating geometry were chosen and the corresponding 2–D flow computations have been carried out for comparison with different angles of attack and in stalled conditions. The simulation results are analyzed. The main features of the boundary layer flow are described, for both the rotating blade and the corresponding 2–D profiles. Computed pressure distributions and aerodynamic coefficients show evidence of less lift losses after separation in the 3–D rotating case, mostly for the inward sections of the blade and the highest angles of attack, which is in agreement with the literature.

scholarly journals Research on the Power Capture and Wake Characteristics of a Wind Turbine Based on a Modified Actuator Line Model

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 282
Author(s):  
Feifei Xue ◽  
Heping Duan ◽  
Chang Xu ◽  
Xingxing Han ◽  
Yanqing Shangguan ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Output Power ◽  
Wind Turbines ◽  
Wind Farm ◽  
Three Dimensional ◽  
Wind Farms ◽  
Line Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Actuator Line Model

On a wind farm, the wake has an important impact on the performance of the wind turbines. For example, the wake of an upstream wind turbine affects the blade load and output power of the downstream wind turbine. In this paper, a modified actuator line model with blade tips, root loss, and an airfoil three-dimensional delayed stall was revised. This full-scale modified actuator line model with blades, nacelles, and towers, was combined with a Large Eddy Simulation, and then applied and validated based on an analysis of wind turbine wakes in wind farms. The modified actuator line model was verified using an experimental wind turbine. Subsequently, numerical simulations were conducted on two NREL 5 MW wind turbines with different staggered spacing to study the effect of the staggered spacing on the characteristics of wind turbines. The results show that the output power of the upstream turbine stabilized at 5.9 MW, and the output power of the downstream turbine increased. When the staggered spacing is R and 1.5R, both the power and thrust of the downstream turbine are severely reduced. However, the length of the peaks was significantly longer, which resulted in a long-term unstable power output. As the staggered spacing increased, the velocity in the central near wake of the downstream turbine also increased, and the recovery speed at the threshold of the wake slowed down. The modified actuator line model described herein can be used for the numerical simulation of wakes in wind farms.

Application of Actuator Line Model for Large Eddy Simulation of Rotor Noise Control

2021 ◽  
Vol 108 ◽  
pp. 106405
Author(s):  
Yann Delorme ◽  
Ronith Stanly ◽  
Steven H. Frankel ◽  
David Greenblatt
Keyword(s):  
Large Eddy Simulation ◽  
Noise Control ◽  
Line Model ◽  
Eddy Simulation ◽  
Rotor Noise ◽  
Large Eddy ◽  
Actuator Line Model

scholarly journals Aeroelastic Performance Analysis of Wind Turbine in the Wake with a New Elastic Actuator Line Model

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1233
Author(s):  
Ziying Yu ◽  
Zhenhong Hu ◽  
Xing Zheng ◽  
Qingwei Ma ◽  
Hongbin Hao
Keyword(s):  
Wind Turbine ◽  
Open Source ◽  
Turbine Blades ◽  
Wake Flow ◽  
Wind Turbine Blades ◽  
Line Model ◽  
Company Limited ◽  
Blade Tip ◽  
Actuator Line Model ◽  
Turbine Blade Design

The scale of a wind turbine is getting larger with the development of wind energy recently. Therefore, the effect of the wind turbine blades deformation on its performances and lifespan has become obvious. In order to solve this research rapidly, a new elastic actuator line model (EALM) is proposed in this study, which is based on turbinesFoam in OpenFOAM (Open Source Field Operation and Manipulation, a free, open source computational fluid dynamics (CFD) software package released by the OpenFOAM Foundation, which was incorporated as a company limited by guarantee in England and Wales). The model combines the actuator line model (ALM) and a beam solver, which is used in the wind turbine blade design. The aeroelastic performances of the NREL (National Renewable Energy Laboratory) 5 MW wind turbine like power, thrust, and blade tip displacement are investigated. These results are compared with some research to prove the new model. Additionally, the influence caused by blade deflections on the aerodynamic performance is discussed. It is demonstrated that the tower shadow effect becomes more obvious and causes the power and thrust to get a bit lower and unsteady. Finally, this variety is analyzed in the wake of upstream wind turbine and it is found that the influence on the performance and wake flow field of downstream wind turbine becomes more serious.

scholarly journals Study on wake-induced fatigue on wind turbine blade based on elastic actuator line model and two-dimensional finite element model

2018 ◽  
Vol 43 (1) ◽  
pp. 64-82
Author(s):  
Hang Meng ◽  
Fue-Sang Lien ◽  
Gregory Glinka ◽  
Li Li ◽  
Jinhua Zhang
Keyword(s):  
Fatigue Life ◽  
Composite Materials ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Turbine Blades ◽  
Beam Model ◽  
Wind Turbine Blades ◽  
Line Model ◽  
Dimensional Finite Element ◽  
Actuator Line Model

Atmospheric and wake turbulence have a great and immediate impact on the fatigue life of wind turbine blades. Generally speaking, wake-induced fatigue accounts for 5%–15% increase of fatigue load on the wind turbine rotor, which definitely threats the safety and economy of the whole wind farm. However, this effect is difficult to simulate which involves multi-wake interaction and fluid structure interaction. To better simulate the wake-induced fatigue on wind turbine blades, a novel elastic actuator line model is employed in this study. The elastic actuator line is a two-way coupling model, consisting of traditional actuator line model and one-dimensional implicit or explicit finite difference method beam structural model, among which the beam model takes gravitational force, aerodynamic force and centrifugal force into consideration. Large eddy simulation method in the NREL SOWFA code is employed to model the turbulence effect, including wake-induced turbulence and atmospheric turbulence. For the fatigue analysis part, the fatigue life of an NREL 5MW turbine blade subjected to upstream wind turbine wake effects is studied using the elastic actuator line model and laminate data available from Sandia Laboratory in the United States. First, the strain and stress on different composite materials, such as uniaxial carbon fibre and biaxial composite material, are recovered by using the sectional force and moment obtained with the one-dimensional beam model and two-dimensional finite element method model, namely BECAS. Second, the stress-life method, rain-flow counting method, shifted Goodman diagram (constant life diagram) and Miners rule are employed to estimate the fatigue life for different composite materials. Noticeably, elastic actuator line largely reduces the computational efforts compared with a high-resolution computational fluid dynamics model, in which each wind turbine blade is fully resolved. Both the characteristics of different composite materials and airfoil geometries will be considered during fatigue analysis. As a result, the above procedure makes the fatigue life estimation more reliable and feasible. In the case studies, the moment time series predicted by elastic actuator line and FAST are compared. The fatigue damage of NREL 5MW wind turbine under turbulent neutral atmospheric boundary layer is calculated, and the fatigue critical section is determined to be at 10.25 m section from root. Finally, in the study of two in-line turbines, the fatigue damage increase by wake flow is 16%, which is close to the results from previous studies.

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